Gas turbine engines, such as those used on commercial and military aircraft, utilize multiple shafts to drive multiple compressor sections. Each of the shafts is connected to, and driven by, a turbine section. By way of example, some gas turbine engines include a high pressure turbine section that is connected to, and drives, a high pressure compressor section via a shaft and a low pressure turbine section that is connected to, and drives, a low pressure compressor section, a helicopter rotor, or another rotating component via another shaft. Alternate gas turbine engines can utilize additional compressor and turbine sections and an additional shaft.
In a typical gas turbine engine construction, the shafts are nested to form a single multi-shaft assembly that runs through the core of the gas turbine engine. This assembly is alternately referred to as a multi-spool assembly. Turbine rotors and compressor rotors corresponding to each shaft are attached to the shaft via a feature such as a spline which transfers torque between the rotors and the shaft. The rotors are maintained in axial position relative to the shaft via a spacer that interfaces with an axial load bearing feature on the shaft and with a shoulder of the rotor.
In some examples, gas turbine engine size and weight constraints reduce the possible size of the radially protruding shoulder. In such a case, the shoulder/spacer arrangement described above can be insufficient to maintain the rotor position relative to the static hardware forward and aft of the rotor.